Hard to Digest Foods: Are You Ready for Some Surprises?

woman holding stomach in pain hard to digest foods

Hard to Digest Foods: Are You Ready for Some Surprises?

By: Julie Mancuso, B.A., R.H.N., JM Nutrition


In this post:

  • list of foods that are hard to digest

  • the underlying reasons why these foods are difficult for our digestive system


Some foods are hard to digest, pure and simple. It’s also a fact that most of us experience some form of digestive problem at one point or another, no matter how robust the digestive system. For many of us, the digestive distress is often caused by the foods we eat. Some of these are well-known while others will surprise.


My personal struggle with digestive health

Reducing digestive distress is naturally important to me professionally, but also personally because I’ve been struggling with all sorts of gastro-intestinal problems the better part of my adult life.

In fact, it was the primary reason why I decided on a career in nutrition over fifteen years ago. You can read about how my own health problems led to my becoming a nutritionist here.

In all honesty, I still find food digestion challenging at times, but it sure has gotten better since I improved my own eating habits. 

I’ve learned a great deal about digestion from extensive research, personal experience, countless consultations with medical practitioners and the experience of my clients. What’s more, I’ve learned a great deal about what foods are hard to digest and which are more benign.

When digestive trouble strikes, it can leave us frustrated, often making it difficult to determine the root causes. Not to mention, the grumbling, churning and general discomfort can sometimes make it hard to enjoy life, especially food. 


Some hard to digest foods are commonly known, while others are not

Well, the solution may just be found in the foods we eat–the analysis of which is the first course of action to take when suffering from digestive distress.

We all know that if we consume large amounts of fatty, greasy, fried, salty or sweet foods, we are likely to trigger some form of digestive discomfort. This can range from slight churning in some to debilitating cramps and pain in others.

But other, less obvious hard to digest foods exist. These foods can also greatly upset the digestive system, causing rumbling, pains and general discomfort.


Hard to Digest Foods


Raw Onions

Raw onions can be hard to digest, for some.

Onions can cause a good deal more than just leaving you with that pungent onion-breath. Some people pass gas and feel digestive discomfort after eating onions in their raw form, while others burp and bloat.

Why are onions hard to digest?

Onions are hard to digest largely because they contain fructans, which are not absorbed well in the small intestine. In fact, as fructans ferment, they can cause a great deal of digestive distress in the form of bloating, gas and diarrhea.

I recommend avoiding raw onions if your digestive system is sensitive, especially if you have a hot date.

Read more about which foods contain fructans in this article from Healthline.

Tips to reduce the digestive upset

If you’re just not prepared to give up those beloved raw onions and must have them on your burger or sandwich, reduce the portion and see if the unpleasant symptoms go away.

You can also cook the onions to reduce the severity of the mentioned symptoms.

Furthermore, you can take digestive enzymes to help to alleviate some of these gastrointestinal disturbances caused by raw onions. 

When considering taking supplements, it is always a good idea to seek the help of a qualified practitioner who can help you select the right digestive enzymes. Please don’t take it upon yourself to do so.


Raw fruits and vegetables

And you thought all fruits and vegetables were good for you…

Well, they no doubt are, for a number of reasons.

Some people, however, experience gastrointestinal problems when certain fruits and vegetables are digested, something that is often omitted from lists of hard to digest foods.

Fruits and vegetables, however, may cause digestive agitation.

Why are some fruits and vegetables hard to digest?

Some fruits and vegetables contain an insoluble fibre—a fibre that does not dissolve in water. While such fibre has the benefit of passing through a person’s system rather quickly, taking other foods with it, and thereby helping to clean out your system, it can also irritate the walls of your colon in the process. This can cause discomfort and even pain.

Therefore, limit eating some vegetables (more on that later) and the skins of fruits and vegetables because they can be harder to digest.

Again, the best way to tell if these are the culprits responsible for your digestive problems is to keep a food log where you note the eaten foods and how they made you feel shortly consumption. Do so for at least a week and try to identify a pattern.

If you find that your digestive system reacts well to fruits and vegetables, then move on to the next food item on the list.


Cabbage and cruciferous vegetables

While cruciferous vegetables such as cabbage, broccoli and cauliflower have a number of important nutrients needed by humans, they also contain indigestible sugars. As a result, some people experience gas, flatulence, belching and abdominal discomfort after ingesting these.

Consume in small quantities, if you suspect cruciferous vegetables aggravate the symptoms.

Keep in mind that cruciferous vegetables are much easier on the digestive system when cooked rather than when eaten raw. If cooking does little to avert the mentioned aches and pains, eliminate them altogether to see if you feel the difference. 



Despite the fact that it contains a good deal of the necessary, healthy fibre, which we all need to promote digestive movement and to keep us full for longer, corn also has another type of fibre called cellulose—something humans have a difficult time breaking down.

The end result: abdominal pain and gas.

If you’re going to consume corn, chew thoroughly to help digestion.



For some time now dairy has been increasingly identified as potentially hard to digest.

It’s important to remember that dairy doesn’t adversely affect all people, only some. It also affects people in varying degrees, so it may be hard to digest for you, but not your loved one.

Furthermore, dairy contains lactose, which is not easily broken down by the digestive system.

As you no doubt know, some people have a complete intolerance to lactose and can become seriously ill upon its consumption. The rest of us, on the other hand, may just experience some gas and bloating, the intensity and frequency of which can vary from person to person.

Some people who reduce their dairy intake, experience immediate improvement in this area.

Pay heed to how you feel immediately after ingesting any dairy product.

Keep a food log that lists how you feel after certain foods are eaten to help you to identify a potential pattern. This applies to any ingested food, not just dairy.

Once you recognize a pattern, limit the food or eliminate it altogether, if need be.

Goat milk vs. cow milk

Goat dairy can be easier to digest because it contains lower levels of a protein called alphaS1-casein than cow’s dairy.

In addition, the fat globules in goat’s milk are much smaller than those of cow’s, further aiding in digestion. Read more about the differences


Spicy foods

There’s a reason why for centuries the Europeans coveted spices like precious stones. Without them, food is bland and, in some cases, barely edible. Used by all cultures, spices are so great in number that most of us aren’t even familiar with many of them.

Spices, however, may impact more than just the flavour of your food. While some people don’t seem to be negatively affected upon the ingestion of spices, others are not as lucky and find them hard to digest.

The matter is complicated even further by the fact that some people are only affected by certain spices, and not others. You’ll have to gauge this yourself by keeping a close eye on how your own body reacts.

Why are spices hard to digest?

The fact is that spices are known to irritate the lining of the esophagus, making them hard to digest, and as such, should be consumed in small amounts by people who are prone to digestive problems.



A sugar-alcohol, sorbitol is an artificial sweetener often found in sugar-free gum and a number of other sweets found at your neighbourhood supermarket.

Sorbitol takes a long time to digest and may cause gas build up as a result, particularly in those who are prone to various digestive conditions.

In addition, chewing gum itself can cause you to swallow a large amount of air, leading to trapped gas and possible discomfort or even pain, making the problem worse.

Read more about Sorbitol and its link to gastrointestinal complaints.


Acidic foods

In short, foods such as tomatoes, oranges and lemons have been found to increase acid reflux. As such, put a limit on their consumption, if you have digestive troubles.

Here’s how you can relieve acid reflux, according to Harvard Health.


Processed foods

Processed foods are packaged foods that are not in their natural form. These foods are often loaded with additives, preservatives, flavourings and other chemicals.

They also contain sodium and frequently, white flour. Most of these foods lack the necessary fibre for proper digestion, and subsequently cause constipation, making them hard to digest.

Prepare foods from scratch and eat them in their most natural form instead. This is an effective way of eliminating the additives found in processed foods as the cause of your digestive disturbances.



We’ve all heard the old saying that beans are hard to digest and cause flatulence. Although we need to dismiss many of the nutrition old wives’ tales as they are simply outdated and have since been proven to be misconceptions, this one is largely true.

Why are beans hard to digest?

Beans contain a complex sugar called oligosaccharide that human cannot digest without the help of digestive enzymes. 

Despite the fact that they are abundant in fibre and high in protein, which are both essential for a healthy diet, the mentioned sugar can cause digestive upset. When it enters the digestive system, it creates gas, which can be quite unpleasant for many.

That is not to say you should strike beans from your diet in their entirety, but consume sparingly if you’re hypersensitive. 


Meats with casing

Meats such as sausages are wrapped in casing, which can be hard to digest for some. This is especially true if the casing is artificial rather than natural. 


Citrus juices

Surprised to see citrus juices on the list of hard to digest foods? Most people are.

Citrus juices, however, can irritate the stomach and cause discomfort in people who are susceptible to digestive problems such as acid reflux, often aggravating such symptoms. Pay close attention and see if juice is responsible.


Carbonated drinks

This one is not much of a surprise.

The vast majority of carbonated drinks aren’t good for overall health anyway. But being acidic in nature, carbonated drinks also distend the stomach, causing discomfort in some. Plain and simple. Avoid.



In addition to the many adverse effects of regularly consuming alcohol in significant amounts, certain alcoholic drinks such as beer have been known to trigger gas in some people—a fact that is not widely known by the general population.

Drinking alcohol can also inflame the lining of the stomach, preventing nutrients from being properly absorbed by your system.

What’s more, alcohol dehydrates the body. This lack of proper water intake in itself can lead to constipation, discomfort and pain. Unfortunately, the bottoms up can make your digestive system bottom out, so pay heed.

Related: How to Make Healthier Alcohol Selections



Some people find gluten difficult to digest. This does not just apply to those stricken with Celiac disease. You may even have a mild sensitivity to it and not even know it. 

Breads, pastas and cereals are the usual suspects here. But there are some less obvious foods that can also contain a fair amount of gluten: beer, certain sauces, dressings and processed foods, and as such, should not be discounted when trying to limit gluten intake.

It’s important to keep in mind that not all people may experience troublesome symptoms after ingesting gluten, but consider its reduction if plagued by ongoing digestive problems. 



The list I offer here is by no means an exclusive one, but more of a sweeping guideline. Some of the foods to which I listed may be common knowledge, but the others not so much. And these are often the ones that people tend to overlook when trying to pinpoint the causes of their digestive troubles.

If you’re a sufferer who’s looking for answers, I strongly encourage you to start with a reduction or elimination of the above foods. Look at the list, follow the suggestions, observe how you feel and discover for yourself. That’s the only sure way of knowing what affects you as an individual. 

As always, I encourage everyone to seek the help of a trained professional in the process to guide you along, offering insight and support. Digestive problems can be overwhelming and exasperating—something with which I can certainly empathize, and as such, they require attention.

If you found this article informative, or know anyone suffering from any type of digestive problem who could find this information useful, please pass it along.


Julie Mancuso Owner of JM Nutrition Nutritionist Toronto Weight Loss Expert

Julie Mancuso

Julie Mancuso is a registered nutritionist and owner of JM Nutrition, who has been counselling clients for over 15 years. Julie’s personalized approach has helped thousands reach their health, wellness and nutrition goals.

Julie regularly lends her expertise to a variety of health publications such as Livestrong, Business Insider, Food Network, MyFitnessPal, Toronto Star, Elle Magazine and many more. For more information, see In The Press.

Julie’s blog has been named one of the Top 100 Nutrition Blogs, Websites and Newsletters to Follow in 2020 by Feedspot. So don’t miss out and subscribe to both her newsletter and blog.